1 files changed, 52 insertions, 37 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index f44612e269a4..d43207c6e467 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1664,8 +1664,9 @@ static void ata_scsi_qc_done(struct ata_queued_cmd *qc, bool set_result,
 
 void ata_scsi_deferred_qc_work(struct work_struct *work)
 {
-	struct ata_port *ap =
-		container_of(work, struct ata_port, deferred_qc_work);
+	struct ata_link *link =
+		container_of(work, struct ata_link, deferred_qc_work);
+	struct ata_port *ap = link->ap;
 	struct ata_queued_cmd *qc;
 	unsigned long flags;
 
@@ -1676,10 +1677,10 @@ void ata_scsi_deferred_qc_work(struct work_struct *work)
 	 * such case, we should not need any more deferring the qc, so warn if
 	 * qc_defer() says otherwise.
 	 */
-	qc = ap->deferred_qc;
+	qc = link->deferred_qc;
 	if (qc && !ata_port_eh_scheduled(ap)) {
 		WARN_ON_ONCE(ap->ops->qc_defer(qc));
-		ap->deferred_qc = NULL;
+		link->deferred_qc = NULL;
 		ata_qc_issue(qc);
 	}
 
@@ -1688,7 +1689,7 @@ void ata_scsi_deferred_qc_work(struct work_struct *work)
 
 void ata_scsi_requeue_deferred_qc(struct ata_port *ap)
 {
-	struct ata_queued_cmd *qc = ap->deferred_qc;
+	struct ata_link *link;
 
 	lockdep_assert_held(ap->lock);
 
@@ -1697,16 +1698,21 @@ void ata_scsi_requeue_deferred_qc(struct ata_port *ap)
 	 * do not try to be smart about what to do with this deferred command
 	 * and simply requeue it by completing it with DID_REQUEUE.
 	 */
-	if (qc) {
-		ap->deferred_qc = NULL;
-		cancel_work(&ap->deferred_qc_work);
-		ata_scsi_qc_done(qc, true, DID_REQUEUE << 16);
+	ata_for_each_link(link, ap, PMP_FIRST) {
+		struct ata_queued_cmd *qc = link->deferred_qc;
+
+		if (qc) {
+			link->deferred_qc = NULL;
+			cancel_work(&link->deferred_qc_work);
+			ata_scsi_qc_done(qc, true, DID_REQUEUE << 16);
+		}
 	}
 }
 
-static void ata_scsi_schedule_deferred_qc(struct ata_port *ap)
+static void ata_scsi_schedule_deferred_qc(struct ata_link *link)
 {
-	struct ata_queued_cmd *qc = ap->deferred_qc;
+	struct ata_queued_cmd *qc = link->deferred_qc;
+	struct ata_port *ap = link->ap;
 
 	lockdep_assert_held(ap->lock);
 
@@ -1723,12 +1729,12 @@ static void ata_scsi_schedule_deferred_qc(struct ata_port *ap)
 		return;
 	}
 	if (!ap->ops->qc_defer(qc))
-		queue_work(system_highpri_wq, &ap->deferred_qc_work);
+		queue_work(system_highpri_wq, &link->deferred_qc_work);
 }
 
 static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 {
-	struct ata_port *ap = qc->ap;
+	struct ata_link *link = qc->dev->link;
 	struct scsi_cmnd *cmd = qc->scsicmd;
 	u8 *cdb = cmd->cmnd;
 	bool have_sense = qc->flags & ATA_QCFLAG_SENSE_VALID;
@@ -1759,22 +1765,23 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 
 	ata_scsi_qc_done(qc, false, 0);
 
-	ata_scsi_schedule_deferred_qc(ap);
+	ata_scsi_schedule_deferred_qc(link);
 }
 
 static int ata_scsi_qc_issue(struct ata_port *ap, struct ata_queued_cmd *qc)
 {
+	struct ata_link *link = qc->dev->link;
 	int ret;
 
 	if (!ap->ops->qc_defer)
-		goto issue;
+		goto issue_qc;
 
 	/*
 	 * If we already have a deferred qc, then rely on the SCSI layer to
 	 * requeue and defer all incoming commands until the deferred qc is
 	 * processed, once all on-going commands complete.
 	 */
-	if (ap->deferred_qc) {
+	if (link->deferred_qc) {
 		ata_qc_free(qc);
 		return SCSI_MLQUEUE_DEVICE_BUSY;
 	}
@@ -1786,38 +1793,46 @@ static int ata_scsi_qc_issue(struct ata_port *ap, struct ata_queued_cmd *qc)
 		break;
 	case ATA_DEFER_LINK:
 		ret = SCSI_MLQUEUE_DEVICE_BUSY;
-		break;
+		goto defer_qc;
+	case ATA_DEFER_LINK_EXCL:
+		/*
+		 * Drivers making use of ap->excl_link cannot store the QC in
+		 * link->deferred_qc, because the ap->excl_link handling is
+		 * incompatible with the link->deferred_qc workqueue handling.
+		 */
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+		goto free_qc;
 	case ATA_DEFER_PORT:
 		ret = SCSI_MLQUEUE_HOST_BUSY;
-		break;
+		goto free_qc;
 	default:
 		WARN_ON_ONCE(1);
 		ret = SCSI_MLQUEUE_HOST_BUSY;
-		break;
+		goto free_qc;
 	}
 
-	if (ret) {
-		/*
-		 * We must defer this qc: if this is not an NCQ command, keep
-		 * this qc as a deferred one and report to the SCSI layer that
-		 * we issued it so that it is not requeued. The deferred qc will
-		 * be issued with the port deferred_qc_work once all on-going
-		 * commands complete.
-		 */
-		if (!ata_is_ncq(qc->tf.protocol)) {
-			ap->deferred_qc = qc;
-			return 0;
-		}
+issue_qc:
+	ata_qc_issue(qc);
+	return 0;
 
-		/* Force a requeue of the command to defer its execution. */
-		ata_qc_free(qc);
-		return ret;
+defer_qc:
+	/*
+	 * We must defer this qc: if this is not an NCQ command, keep
+	 * this qc as a deferred one and report to the SCSI layer that
+	 * we issued it so that it is not requeued. The deferred qc will
+	 * be issued with the port deferred_qc_work once all on-going
+	 * commands complete.
+	 */
+	if (!ata_is_ncq(qc->tf.protocol)) {
+		link->deferred_qc = qc;
+		return 0;
 	}
 
-issue:
-	ata_qc_issue(qc);
+free_qc:
+	/* Force a requeue of the command to defer its execution. */
+	ata_qc_free(qc);
 
-	return 0;
+	return ret;
 }
 
 /**